Exploring the addictive nature of cigarettes

Why is it so hard to quit smoking? That was the question tackled recently by BBC World Service's CrowdScience show. There are 1 billion smokers across the world, host Marnie Chesterton pointed out before talking with several researchers. Among them were University of California, San Francisco's Neal Benowitz, MD, who discussed the highly addictive nature of nicotine — "It's probably the most addictive drug that we have," he said — and Stanford's Keith Humphreys, PhD, who provided a bit of history about tobacco products and explained what happens when people are addicted.

"You show them any cue associated with their use and when you put those people in an MRI machine you can see activation in their brain," he explained. "It's sort of like their brain is like, 'Hey, something's important going on. Pay attention to it.'"

He also discussed the complicated nature of addiction -- and the many challenges of combating it. "Our ability to resist urges is controlled by the brain, but it's also really influenced by our behavior and environment," he pointed out. "So just as an example, raising taxes on cigarettes reduces use, even among heavy smokers. So that suggests there is some ability, even among addicted people, to exercise control."

Chesterton goes on to describe imaging work being done in a Stanford psychology lab and what researchers are learning by looking in the brains of addicted smokers. "With this information you could imagine designing interventions that are specifically targeted to change brain activity in these award circuit regions, and there are different ways we're thinking about doing that and that people are trying right now," said postdoctoral fellow Kelly Hennigan, PhD.

The entire show is worth a listen -- whether you smoke (and hopefully you don't) or not.

The scenario many of us learned in school is that two X chromosomes make someone female, and an X and a Y chromosome make someone male. These are simplistic ways of thinking about what is scientifically very complex.